The problems that arise for such a product dispenser involve, in particular, the need for inexpensive manufacturing processes. In effect, since samples are not generally intended for sale, the manufacturing cost must be as low as possible. It is therefore important to have devices whose parts are easy to produce in large series and the mounting of which can be done simply. Furthermore, since the samples are used mainly for advertising purposes, it is desirable to be able to visibly affix the brand, the logo, or any other distinctive sign corresponding to the product contained in the dispenser. Likewise, it is desirable to provide a device in a form that is original and practical for use. For example, in the case of samples to be included in magazines or journals, it is necessary for the dispenser to have a greatly reduced thickness.
The dispensing device according to the invention can also be applied in the pharmaceutical field. In this particular field, it is important for the dose of product contained in the dispenser to be completely expelled. Furthermore, it is also important for the spray to be of good quality.
For example, known through French Patent No. A-2,443,980 is a disposable sprayer produced by the fusion of a sheet of plastic material, placing between it a container as well as two channels of vortex connected to a spray opening. By pressure on the container whose walls are produced by sheets of plastic, product is discharged into the vortex channels, then through the spray opening, creating a stream of sprayed product. This disposable sprayer does not, however, make it possible to expel a defined dose of product. Moreover, the production of vortex channels by the fusion of two sheets of plastic is rather imprecise and random. According to a version of this sprayer, the container is divided into two chambers by a partition that is broken under the action of the pressure. One chamber is filled with a fluid while the other contains the product and air. Furthermore, the container is separated from the spray opening by a point of rupture. In a first step, when one presses on the container, the partition breaks, and the two fluids are to varying degrees mixed together with air. In any case, the mixture thus obtained cannot be homogeneous. By increasing the pressure, the point of rupture breaks and the nonhomogeneous mixture is discharged towards the spray opening. The stream leaving the opening is sometimes composed of the first fluid, sometimes of the second fluid, and sometimes of air, but is never composed of a homogeneous mixture of the three. It results that the stream is sometimes purely aqueous and sometimes biphasic. Its quality is therefore not constant.
The problem that the present invention proposes to solve is the production of an inexpensive dispensing device that provides a good quality of spray of a single dose of product in a constant and precise volume. In certain applications, particularly advertising applications, the dispensing device must meet certain dimensional requirements; in particular, it must have a reduced thickness.